Door locks used nowadays, in order to meet different size requirements, are manufactured in two different sizes to accomodate the width of the frame post in a door. Therefore, lock manufacturers have to prepare different molds for making different sizes of locks, and retailers are obliged to devote more shelf space for storing them. Moreover, since the two different sizes of locks are very similar to each other, generally 60 mm and 70 mm, the consumers would always be confused unless they have specific knowledge about the size of locks.